QS 5W-30 Full Syn, 1234 MI, 00 Nissan Frontir 3.6L

Long post, sorry. UOA at the bottom for the tl/dr folk. This was a very short interval between UOAs because I wanted to see if the high wear on the first one was still happening. Apparently it still is, at least it looks that way judging from the high wear metals after only 3 months. While 'testing margin of error' could account for some of it, it looks like higher wear in 1000 miles than what most people post after 4 times that. I had it gone over by a local certified shop, who found no reason for the high wear. They found some minor stuff (bad knock sensor, fan clutch that didn't always...clutch), but nothing to account for the unusual wear. I cut open the oil filter, and didn't see any tears, carbon bits, or metal flakes. Beyond that, I don't know what to examine in a used filter. There was quite a bit of good oil advice in my first UOA for this vehicle ( post 2385929 ) but no real consensus as to what the cause could be. So here's what I think: Vehicle Abuse! This wear level is likely explained by the mostly short trips this vehicle sees. Last year and this year, the norm has been short trips of 3-10 miles with at least an hour between them. This summer, most trips have been 2 -3 miles, with only a minute or two warming up time before moving out. Of the 1200 miles on this oil, probably 8000 was in 3 mile segments with an hour (or more) to cool down before the next trip. This winter looks like it will be even worse from a trip length perspective--almost exactly 2 miles per trip. However there should be fewer of them. I should only be driving this vehicle to work in the morning and home in the evening, with no trips during the day. So, here's what I plan to do. I'm going to do another very short OCI. For that I'm using a cheap synthetic: O'Reilly 0W-20 Syn ( post 2415164 ) because I don't want to spend a lot on really good oil I'm just going to dump in a few hundred miles. Now that it has turned cold (30 degrees this morning) my theory is the thinner the oil the better--maybe I'll get some lubrication out of it. I'll pull a sample in another 3 or 4 months and see if the wear has decreased any with the thinner oil. If it has, then I'll put in something good, Pennzoil Ultra probably. If not, then I'll be back here to explore the topic further. If all goes according to plan, this will be the last winter this poor pickup gets abused like this. Next year I'll (hopefully) be in an office 0.8 miles from home. With no need to carry my tools around, that's walking distance even in winter. Until then I'd like to minimize the damage, and I welcome advice anyone cares to give. Anyway, here's the UOA:
Originally Posted By: BlackstoneLabs
Wear dropped quite a bit in this second sample, but a lot of that is likely due to the much shorter oil run this time around. Still, we like the improvement, and until we can be sure of the cause of the high wear (or at least that it's gone away), we'd suggest staying with shorter oil changes like that. Silicon was the only increase; unless you've had work done to the engine recently, that may show dirt, so it wouldn't be a bad idea to check the air filter, and look for cracks or leaks downstream to see if any unfiltered air is getting in. That could cause high wear.
2000 Nissan Frontier 3.3L V6 with 54,000 miles on vehicle

MI/HR on Oil     1,234        4,457
MI/HR on Unit   53,980       52,721      Universal
Sample Date   10/17/11     06/25/11      Averages

ALUMINUM            10           20            4
CHROMIUM             2            2            1
IRON                43          129           14
COPPER               5           14            4
LEAD                10           40           10
TIN                  1            0            0
MOLYBDENUM          59           82           80
NICKEL               0            1            0
MANGANESE            1            3            1
SILVER               0            0            0
TITANIUM             0            0            0
POTASSIUM            2            7            5
BORON               15          103           44
SILICON             17           16           11
SODIUM               8           19           38
CALCIUM           2364         3159         2219
MAGNESIUM           11           23          119
PHOSPHORUS         764          892          682
ZINC               850         1056          829
BARIUM               0            0            0

PROPERTIES           10/17/11      06/25/11     Should Be
SUS Viscosity @ 210°F    59.3          60.5         54-61 
cSt Viscosity @ 100°C   10.02         10.35      8.5-10.8 
Flashpoint in °F          385           360          >365 
Fuel %                     <0.5          TR          <2.0 
Antifreeze %              0.0           0.0           0.0 
Water %                   0.0           0.0           0.0 
Insolubles %              0.3           0.4          <0.6 
Silicon is still high - I suspect there is a lot of dirt in the engine. Check your air filter, filter housing, and ducting very carefully for leaks, just like the lab said.
Merritt Island FL, USA
I think this plan you have is good as any. With wear showings like this you have to think outside the box and play around until you find a good combo. If your plan doesn't work I think your best bet may be to stick with the cheapest oil you can find and keep OCI's short. Addyguy is right, check the air intake system.


Thread starter
Originally Posted By: addyguy
Silicon [snip] Check your air filter, filter housing, and ducting very carefully for leaks [snip]
Did that, found nothing. I also replaced the air filter at the beginning of this oil run. I asked the shop to check it too, and they didn't find any intake leaks.